666409156608 has 480 divisors, whose sum is σ = 2092726056960. Its totient is φ = 186667499520.

The previous prime is 666409156607. The next prime is 666409156643. The reversal of 666409156608 is 806651904666.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (666409156607) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 336739363 + ... + 336741341.

It is an arithmetic number, because the mean of its divisors is an integer number (4359845952).

Almost surely, 2^666409156608 is an apocalyptic number.

666409156608 is a gapful number since it is divisible by the number (68) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 666409156608, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1046363028480).

666409156608 is an abundant number, since it is smaller than the sum of its proper divisors (1426316900352).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

666409156608 is a wasteful number, since it uses less digits than its factorization.

666409156608 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2071 (or 2045 counting only the distinct ones).

The product of its (nonzero) digits is 11197440, while the sum is 57.

The spelling of 666409156608 in words is "six hundred sixty-six billion, four hundred nine million, one hundred fifty-six thousand, six hundred eight".